Roof vent and method for installation

ABSTRACT

A roof ventilation apparatus for a sloped roof having a cap and base plate is provided. The cap has a top surface and a bottom surface. The bottom surface has a flange that defines an opening to a cavity formed between the top and bottom cap surface. The cavity provides a path for air exchange from a roof opening through an air passage formed between the flange and cap top. The base plate has a flange surrounding a rim that fits inside the cap bottom cavity. The base plate preferably is shaped such that when installed on the sloped roof the cap entirely covers the base plate. Alternatively, a roof vent base plate with a flange having an angled edge configured to channel moisture is described. In addition, a method of installing a roof ventilation apparatus having a base plate and roof cap on a sloped roof is described.

FIELD OF THE INVENTION

The present invention is directed to flashing for roof vents. More specifically, the present invention is directed to a roof vent for ventilating a building with a pitched roof and methods for installing roof vents.

BACKGROUND OF THE INVENTION

There are various designs in existence for providing ventilation for the areas beneath building roofs. The ventilation of such areas is desirable to reduce the accumulation of heat and to reduce the accumulation of moisture in the attic or other spaces immediately below the roof. In providing ventilation, it is important to prevent the entry of water into the building structure through the vent. Also, it is desirable to prevent debris and small animals from entering the building structure though the vent. Ultimately, the benefits of a properly constructed roof vent will prolong the life of the roof, virtually eliminate leaks caused by ice dams, reduce cooling bills, and reduce moisture build up in the attic that can lead to rot.

To protect buildings and their contents from water damage, roofers repair and install roofs made of tar, asphalt and gravel; rubber, thermoplastic; metal; or shingles made of asphalt, slate, fiberglass, wood, tile, or other material. There are two types of roofs—flat and pitched (sloped). Pitch is the change in roof height for a horizontal distance (e.g., a 4 pitch roof changes height by 4 inches for every 12 inches of horizontal distance). Many commercial, industrial, and apartment buildings have flat or slightly sloping roofs for drainage (i.e., roofs with minimum pitch of less than 2 pitch). Many residential houses have pitched roofs.

Flashing has been used for decades to weatherproof roof penetrations. Flashings protect the roof where moisture could get under it, such as at joints in the roof, places where a vent pipe or chimney pokes through, a valley where two roof surfaces meet, or where a roof meets a wall. Some flashings are installed before the roofing goes on, others are put in place along with the roofing. Flashing is widely used with shake, composite and wood shingles and roll roofing. Like many flashing pieces, the vent flashing often is installed between shingle courses.

Flashings for pipes and other roof penetrations are sometimes made from thin sheet metal that is cut and formed into the desired shape by construction workers at the building site. The flashing is usually formed from one piece of sheet material that has a central opening cut therein to fit about the roof penetration. Thereafter, a sealing material, such as caulk or tar, is placed about the juncture of the roof penetration and the central opening in the sheet material.

Roof vents (or turbine vents) come in many forms, but generally include some type of weather-shedding hood and a flange around the base that forms a seal between the vent and the surrounding roofing material. Some vents have a pipe that penetrates the roof surface and is exposed above the roof. Also, some vents have a tubular outside vent stack cover which is secured to a substantially flat roof flashing base plate. See for example U.S. Pat. No. 5,778,611 to Michel, “Vent Extension Flashing Assembly”, issued Jul. 14, 1998. In other roof vents, the pipe remains exposed through the base plate flashing assembly. See for example U.S. Pat. No. 4,333,660 to Cupit, “Seal Device for Pipe Projecting through Roof”, issued Jun. 8, 1982. Ultimately, to make a roof vent installation watertight, the most basic rule is to cover the vent flanges with roof material on the high side towards the roof ridge and along the edges of the vent, and cover the roofing material with the vent flange on the low side.

In addition, roof vents are sometimes assembled from essentially planar sheet material so that a portion of the sheet material about the central opening lies in approximately the same plane as the remaining portion of the sheet material. Such construction leads to increased likelihood of leakage at the central opening. An example of such a roof vent is disclosed in U.S. Pat. No. 4,570,396 to Struben, “Roof structure for mobile homes”, issued Feb. 18, 1986.

A need exists for an inexpensive roof vent system that channels water away from the roof opening with improved moisture sealing capability while maintaining simplicity in the installation process. The present invention provides a solution to these needs, and offers other advantages over the prior art.

SUMMARY OF THE INVENTION

In accordance with one embodiment of the invention, a roof ventilation apparatus configured and arranged to be installed on a sloped roof over a roof opening is provided. The roof ventilation apparatus includes a cap and a base plate. The cap has a top surface and a bottom surface. The top surface is configured to cover at least a portion of the roof opening. The bottom surface has a flange that defines an opening to a cavity formed between the top and bottom cap surface. The flange extends outward relative to the cavity. The cavity is configured to provide a path for air exchange from the roof opening through an air passage formed between the flange and the cap top. The base plate has a flange surrounding a rim. The rim preferably is shaped such that the rim fits inside the cap bottom cavity. The base plate preferably is shaped such that when installed on the sloped roof the cap entirely covers the base plate. Alternatively, a roof vent base plate with a flange having an angled edge configured to channel moisture is described. In addition, a method of installing a roof ventilation apparatus having a base plate and roof cap on a sloped roof is described.

Additional advantages and features of the invention will be set forth in part in the description which follows, and in part, will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a roof ventilation apparatus installed on a roof with a partial cutaway showing roof sheathing.

FIG. 2 is a perspective view of a roof ventilation apparatus installed on a sloped roof and revealing the attic underneath the sloped roof.

FIG. 3 is a cutaway view of a roof ventilation apparatus.

FIG. 4 is an exploded cutaway view of a roof ventilation apparatus.

FIG. 5 is an exploded view of a roof ventilation apparatus.

FIG. 6 is a perspective view of a base plate covered by roofing paper and a partially cutaway view of roof sheathing.

FIG. 7 illustrates alternative embodiment shapes of a base plate in accordance with the present invention.

DETAILED DESCRIPTION

FIGS. 1 and 2 are a series of perspective views presenting a roof ventilation apparatus 100 to be used on sloped roofs. The pitch, or slope of the roof, should preferably be greater than 2 inches. FIG. 1 illustrates a partial cutaway view of a shingle roof with a roof sheathing 107 underneath. In FIG. 2 the roof ventilation apparatus 100 is installed on a shingle roof to ventilate an attic 101. It will be appreciated by those skilled in the art that the roof ventilation apparatus 100 can be used to ventilate most types of commercial and residential roofs. Moreover, shakes, tiles, and other roofing materials can be used in alternative of shingles 114. FIG. 2 also illustrates a ridge 105 and roof deck 116.

FIG. 3 is a cutaway perspective view illustrating the layers of parts used that together form a preferred embodiment of the roof ventilation apparatus 100. FIG. 4 is an exploded partially cutaway view of the roof ventilation apparatus 100 with the same parts shown on FIG. 3. Base plate 108 is positioned on roof deck 116 having an opening 120. The opening 120 can be any regular or irregular shape. Base plate 108 is attached to roof deck 116 with nails 124. However, it will be appreciated by those skilled in the art that other forms of attachment such as screws and adhesives may be used without departing from the scope and spirit of the present invention. Roofing paper 106 is set over base plate 108. In the alternative, asphalt—impregnated felt or other underlayments may be added or substituted for roofing paper 106. Caulk bead 118 is used to seal roofing paper 106 over base plate 108 and base plate rim 110. It will be appreciated by those skilled in the art that the caulk bead 118 may be omitted or other forms of adhesive may be used instead of caulk bead 118. Vent cap 102 is fitted over base plate 108 such that vent cavity 112 encircles base plate rim 110. Vent cavity 112 and base plate rim 110 can be formed in any shape. In preferred embodiments, base plate rim 110 has a diameter (e.g. 8 inches) smaller than that of the cap bottom surface cavity 112 (e.g. 8½ inches). It will be appreciated by those skilled in the art that vent cap 102 can be either loosely or tightly fitted around base plate 108. Bottom surface flange 104 entirely covers base plate 108 after installation. Shingles 114 are then installed over cap bottom surface flange 104. Moisture is not likely to enter the roof opening 120 because bottom surface flange 104 entirely covers base plate 108 over roofing paper 106. When fully installed, only the vent cap top 103 is visible on the roof.

FIG. 5 is also an exploded view of the roof ventilation apparatus 100. FIG. 5 shows the base plate 108 being installed on a roof deck 116. It will be appreciated by those skilled in the art that the base plate 108 can be installed on any type of roof deck and roof sheathing such as plywood. Furthermore, the roof ventilation apparatus 100 is preferably constructed from a twenty to twenty-five gauge galvanized steel. The majority in this field prefer to utilize a twenty-five gauge due to the lighter weight and manageability as compared to the heavier twenty gauge steel. As an alternative other materials may be used for constructing the roof ventilation apparatus 100, such as aluminum, copper, urethanes, and polymers. However, it will be appreciated by those skilled in the art that galvanized metal is preferred over polymers because polymers tend to crack and curl with changing weather and are less weather resistant than metal.

FIG. 6 illustrates the base plate 108 covered by the roofing paper 106. A partial cutaway in FIG. 6 reveals the roof deck 116 underneath both the base plate 108 and roofing paper 106. FIG. 7 illustrates some possible alternative embodiments 201 through 205 of the base plate 108. Alternative embodiment base plates 201 and 204 show peaked corners 122 that angle moisture away from the base plate rim 110. Another alternative embodiment (not shown) could have a peaked corner off center or even moved to one corner such that the angle goes from a peak at one corner to a low point at another corner. Alternative embodiment base plate 205 has dubbed corners that channel moisture down the sides of base plate 108 away from base plate rim 110. When installed, both the peaked and dubbed corners point towards the high side of the roof (i.e., towards the roof ridge 105) and prevent the entry of moisture into the roof opening. Alternative embodiment base plates 202 and 203 illustrate alternative shapes that channel moisture away from the base plate rim 110 along a curved edge but otherwise similar to the mechanism provided for in the peaked and dubbed corners of alternative embodiment base plates 201, 204, and 205.

It is to be understood that even though numerous characteristics and advantages of various embodiments of the present invention have been set forth in the foregoing description, together with details of the structure and function of various embodiments of the invention, this disclosure is illustrative only, and changes may be made in detail, especially in matters of structure and arrangement of parts within the principles of the present invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

1. A roof ventilation apparatus configured and arranged to be installed on a sloped roof having an opening therethrough, the roof ventilation apparatus comprising: a cap having a top surface and a bottom surface, the top surface configured to cover at least a portion of the roof opening, the bottom surface having a flange defining an opening to a cavity formed between the top and bottom cap surface, the flange extending outward relative to the cavity, the cavity configured to provide a path for air exchange from the roof opening through an air passage formed between the flange and the cap top; and a base plate having a flange surrounding a rim, the rim being shaped such that the rim fits inside the cap bottom cavity, the base plate being shaped such that when installed on the sloped roof the cap entirely covers the base plate.
 2. The roof ventilation apparatus of claim 1 wherein the base plate flange is substantially planar and extending outward from the rim.
 3. The roof ventilation apparatus of claim 1 wherein the base plate rim extends substantially perpendicular from the base plate flange.
 4. The roof ventilation apparatus of claim 1 wherein the base flange has dubbed corners such that when installed on a sloped roof, the dubbed corners can be oriented towards a roof ridge.
 5. The roof ventilation apparatus of claim 1 wherein the base plate and vent cap are prepared from galvanized steel.
 6. The roof ventilation apparatus of claim 1 wherein the base plate and vent cap are prepared from a flexible, durable, and weather resistant material.
 7. A roof vent base plate that is operatively configured to be installed on a sloped roof having an opening therethrough, the roof vent base plate comprising: a flange having at least one angled edge, the flange surrounding a rim, the rim being shaped such that the rim fits inside a cap cavity.
 8. The roof vent base plate of claim 7 wherein the at least one angled edge comprises dubbed corners configured and arranged to be oriented towards a roof ridge.
 9. The roof vent base plate of claim 7 wherein the at least one angled edge comprises peaked corners configured and arranged to be oriented towards a roof ridge.
 10. The roof vent base plate of claim 7 wherein the at least one angled edge comprises a curved edge configured and arranged to be oriented towards a roof ridge.
 11. A method of installing a roof ventilation apparatus on a sloped roof having an opening therethrough, comprising steps of: mounting a base plate to a sloped roof deck or roof sheathing; fixing roofing paper having an opening therethrough over the base plate; nailing a roof vent cap over the rim of the base plate; and fitting shingle courses over a flange of the base plate in a manner such that only the roof vent cap is exposed.
 12. The method of claim 11 further comprising a step of sealing the rim of the base plate with a bead of caulk. 